Spherical module connectors

ABSTRACT

Elongate rigid flotation modules are coupled together along deck and submerged portions to provide a stable floating platform. The submerged portion on one of the floating modules is spherically shaped and a cylindrical extension from the submerged portion of an adjacent flotation module is configured to mechanically cooperate with the spherically-shaped portion in a sealed relationship. Evacuating the water from the now-sealed cylindrical extension creates a pressure differential which holds the submerged portions of the flotation modules together. This manner of seating between the cylindrical extension on the spherically-shaped surface allows precise positioning of the deck portions prior to their interconnection.

United States Patent [191 Rosenberg SPHERICAL MODULE CONNECTORS [75]Inventor: Edgar N. Rosenberg, San Diego,

Calif.

[73] Assignee: The United States of America as represented by theSecretary of the Navy, Washington, DC.

[22] Filed: Aug. 14, 1972 [21] Appl. No.: 280,699

114/.5 F, .5 T, 65 A; 9/8 P; 61/69 A, 43, 46.5, 53; 252/39 [56]References Cited UNITED STATES PATENTS 1,800,310 4/1931 McGee 61/69 A3,640,079 2/1972 Therisien et al. 61/69 A 3,592,155 7/1971 Rosenberg114/.5 T 3,347,052 10/1967 Steitle et a1 61/46.5 2,946,566 7/1960Samuelson 61/46.5 X 3,159,130 12/1964 Vos 9/8 P X 1,678,127 7/1928 Smith61/43 [451 Jan. 15,1974

629,135 7/1899 Nixon et al. 61/43 3,234,130 2/1966 Nixon et a1. 252/393,258,425 6/1966 Burke 252/39 1,371,846 3/1921 Braestrup 114/65 A [5 7ABSTRACT Elongate rigid flotation modules are coupled together alongdeck and submerged portions to provide a stable floating platform. Thesubmerged portion on one of the floating modules is spherically shapedand a cylindrical extension from the submerged portion of an adjacentflotation module is configured to mechanically cooperate with thespherically-shaped portion in a sealed relationship. Evacuating thewater from the now-sealed cylindrical extension creates a pressuredifferential which holds the submerged portions of the flotation modulestogether. This manner of seating between the cylindrical extension onthe sphericallyshaped surface allows precise positioning of the deckportions prior to their interconnection.

2 Claims, 4 Drawing Figures PATENTEUJAH 15' m4 SHEET 1 [IF 3 FIGPATENTED JAN 15 I974 SHEET 2 Hf 3 FIG3 PATENTEDJAH 15 1914 3.785313 sum3m 13 SPHERICAL MODULE CONNECTORS STATEMENT OF GOVERNMENT INTEREST Theinvention described herein may be manufactured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION Off-shore platform designs are many andvaried. Barge-type platforms floating on the surface of the waterlargely proved to be unsatisfactory where stability is concerned due totheir reaction to surface waves. Flotation platforms assembled from anumber of sparbuoy-like structures largely have avoided the surface wavereaction of the barge platforms yet their relatively marginal buoyingcapability renders them unsuitable where substantial loads need to besupported. Both stability and greater load-support capability wereprovided in the Floating Platform" shown in U. S. Pat. No. 3,592,155issued July 13, 1971 to Edgar N. Rosenberg. These large, cast moduleshave a small neck for minimizing wave reaction and a large body forincreased buoyancy. However, difficulties of another type becameapparent when adjacent modules were coupled together. Even low seastates and slight winds created relative motion between the uncoupledmodules and the coupling procedure was unduly complicated and hazardous.Because of the relatively low torsional and tensile strengthcharacteristics of the concrete modules, connecting either adjacentsurface or submerged portions, one before the other, should be avoided.Simultaneous coordinated alignment and connection avoids theself-destructive stresses from being created but is impossible inpractice due to the relative motion. Interconnection of the adjacentconcrete modules would be greatly facilitated if the joint betweenadjacent surface or the submerged portions of the modules couldaccommodate at least slight relative motion between adjacent modulesduring the interconnection process.

SUMMARY OF THE INVENTION An apparatus for coupling the submergedportions of flotation modules includes a spherical surface disposed onthe submerged portion of one flotation module and a means defining awater-filled cavity carried on the submerged portion of an adjacentflotation module having an annular surface configured to correspond tothe spherical surface. Suitable means pull the spherical surface andannular sealing surface together in a sealing relationship and water isevacuated from the nowsealed cavity creating a pressure differential toensure a nonrigid coupling of the adjacent flotation modules.

A prime object of the invention is to provide a coupling betweenflotation modules.

Another object is to provide a nonrigid coupling allowing precisealignment of the surface connectors of a flotation module.

Still another object is to provide a coupling apparatus suitable forjoining concrete flotation modules.

Yet another object is to provide a coupling serving to define apassageway between adjacent flotation modules. 1

These and other objects of the invention will become more readilyapparent from the ensuing specification when taken with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric depiction of aflotation module being joined to a platform of flotation modules.

FIG. 2 is a side view of a preferred moduleconnection technique.

FIG. 3 is a cross-sectional view showing one embodiment of the submergedcoupling.

FIG. 4 is a cross-sectional view of a reinforced coupling shown in FIG.3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,FIGS. 1 and 2 show representative configurations of a flotation module10 in the process of being secured to a platform formed of similarlyconfigured, interconnected flotation modules. Besides being cheaper thansteel, concrete preferably is used as the module building material forit resists marine organisms and is noncorrosive. However, even whenreinforcing rods are cast into each module care must be taken that themodule is not subjected to destructive torsional or tensile forces.Because of the great weight of these concrete modules, selfdestructiveforces may be created by careless handling. Thus, two representativemethods of the steps taken to position and interconnect the modules areshown in FIGS. 1 and 2.

Each module is designed with a neck 11 having a reduced cross-sectionalarea. This reduced area minimizes the unstabilizing buoyancy effects ofrising and falling surface waves in much the same manner as aconventional sparbuoy. A deck portion 12 is held above the surface ofthe water by an outwardly flaring portion 11a and is suitably modifiedfor the job at hand. For the purpose of example, adjacent ones of themodules are pivotally joined by loose fitting pins 13 driven throughaligned bores 14 provided in laterally reaching extensions 15.Complimentary bores carried in adjacent modules are aligned and theadjacent modules are coupled at their upper ends. By ballasting andweighting different internal compartments of the individual flotationmodules, the attitude of a single module with respect to the platform offlotation modules is adjustable to permit the pivotal interconnectionvia the pins and bores. After the pivotal interconnection has beencompleted further internal flooding or reballasting causes acounterclockwise rotation bringing its submerged portion 16 into theproximity of a submerged portion 16a of an adjacent flotation module10a. This procedure avoids self-destructive forces from being createdprior to and during the coupling operation.

A more expedient, cheaper method of bringing flotation module 10 intothe close proximity of an adjacent flotation module 10a is depicted inFIG. 2. In this approach the module is an integral unit having a singleinternal chamber lending itself to simple flooding and evacuation ofwater to bring its submerged portion 16 to the same level and next to anadjacent module 10a. Once the appropriate vertical positioning anddisposition'have been attained, remotely located machinery connected tocables 17 draws submerged portion 16 against submerged portion 16a ofthe adjacent module for interconnection. When this method of orientingthe modules with respect to each other is followed and the deck portionsare connected after ths submerged portions are joined, the discreteshaping of the submerged portions prevents damaging stress from beingcreated and markedly contributes to the improved capabilities of theflotation module platform.

A spherically-shaped surface 18 is formed by casting and smoothing onthe outer surface of submerged portion 16 and the smooth continuoussurface is fashioned to present a regular spherical contour. Acylindricallyshaped extension 19 is integrally molded with submergedportion 16a and carries an annular sealing surface 20 on its outwardmostprojection. The annular sealing surface has a concave cross-sectionalradius of curvature defined by a spherically-shaped surface 18. Thus, ascable 17 draws the spherically-shaped surface and the annular sealingsurface together, because they are both smooth, have no irregularities,and are correspondingly shaped, the two surfaces abut one another in asealing relationship. Pumping the water from the cavity enclosed by thecylindrically-shaped extension, via a fitting 21, creates a pressuredifferential across the walls of the extension which holds flotationmodule and flotation module 10a together. Being held together in such amanner allows a slight ball-and-socket coaction across the movablejoint" to allow precise alignment and interconnection of the adjacentdeck portions 12 and 120.

Since experience has shown that it is difficult to maintain the sealedrelationship between the annular sealing surface and thespherically-shaped surface, a resilient sealing ring 22 is carried in anappropriately shaped groove 23. The ring is optionally hollow or ofhomogeneous cross section and projects outside the groove to resilientlyengage the spherically-shaped surface. Because the ring is to functionin the corrosive marine environment and must withstand a grating actionas it is seated to abut the spherically-shaped surface, the resilientsealing ring is chosen from materials having suitable properties.Sealing is enhanced between the exposed outwardly facing surface of theresilient sealing ring and the spherically-shaped surface by coating therings outer surface with a nonreactive grease compound 24. In additionto ensuring a seal, the grease coating further minimizes the abrasivewearing of the ring by the spherically-shaped surface as the adjacentdeck portions are maneuvered into their proper mutual alignment.

Employing the aforedescribed structure provides a long-lasting sealedconnection between the submerged portions of flotation modules forprolonged periods of time. Possible deterioration of the resilientsealing ring due to the water and to marine organisms is checked byhaving divers completely coat the exposed surfaces of the ring withadditional layers of the silicone grease. Should there by any leaking,periodically attaching a pump to fitting 21 removes the leaked water. Anadvantage of this design is that should it be desired to remove aflotation module because of damage, for example, merely flooding thecylindrically-shaped extension breaks the pressure differential bond andthe spherically-shaped surface is free to drift away from the annularsealing surface. Creating a slight over-pressure in the flooded cavityensures the separation of the two surfaces.

Where a stronger more permanent juncture between adjacent flotationmodules is required, or one which will better withstand the corrosiveeffects of the marine environment, the alternate embodiment shown inFIG. 4 is chosen. Like elements in this modification are given likereference characters with respect to the aforedescribed configuration,the most important being a mechanically cooperating spherically-shapedsurface 18 and an annular sealing surface 20 interposing a resilientsealing ring 22.

At least one tensioning threaded rod 25 reaches through enlarged holes26 in the submerged portion of each module. Large washers 27 compressingO-rings 28 are screwed onto threaded rod 25 to draw the adjacent modulestogether and to compress the resilient sealing ring for isolating thecavity contained by the cylindrically-shaped extension 19. Next,removable plugs 29 and 29a are taken from openings 30 and 30a previouslymolded in the flotation modules 10 and 10a. Since these flotationmodules each are cast to define a single chamber in communication withthe surface, the passageway created by removing the plugs from theopenings also is in communication with the air at the surface. The waterpreviously filling the cavity above the level of the plugs now drainsinto the submerged portions of the flotation modules. Merely pumpingthis water and the water remaining below the level of the plugs from thecavity causes the ambient water pressure to push the spherically-shapedsurface more forcefully against the annular sealing surface.

When these modules were cast, a plurality of reinforcing rods 31 wereincluded and occupy an annular chamber contained by cylindrically-shapedextension 19. The rods from the adjacent modules reach toward each othervand either stop short or overlap when greater strength is called for.Thusly modified, it is simple to permanently join the adjacent flotationmodules together after the deck portions have been connected.

An innerform or cofferdam wall 32 coaxially defines the inner limits ofan annular casting chamber occupied partially by the reinforcing rods. Afitting 33 reaching through the cofferdam wall allows concrete slurry tobe pumped into the casting chamber and after the concrete has hardened,the cofferdam optionally is removed for reuse in another moduleinterconnection.

The reinforced concrete cylinder removes any uncertainty as to thepermanency of the sealing joint created by spherically-shaped surfaceand the annular sealing surface. In addition, the hardened concretedefines a passageway between the two openings for communication andaccess between adjacent flotation modules. Although not specificallyshown, electrical wiring and life support conduits optionally are moldedinto the concrete cylinder. Fittings for mounting watertight hatches arealso included when such closures are needed.

Obviously, many modifications and variations of the present inventionare possible in the light of the above teachings, and, it is thereforeunderstood that within the scope of the disclosed inventive concept, theinvention may be practiced otherwise than specifically described.

What is claimed is:

1. An apparatus for coupling the submerged portions of flotation modulescomprising:

means providing a spherical surface disposed on the submerged portion ofone flotation module; means carried on the submerged portion of anadjacent flotation module for defining a water-filledcylindrically-shaped cavity integrally extending from said adjacentflotation module, both flotation modules are provided with openings incommunication with said cavity and after the water has been evacuated,create a passageway between the flotation modules;

means mounted on the outwardmost extreme of the means defining a cavityforming an annular sealing surface having a cross-sectional radiuscorresponding to said spherical surface;

at least one tensioning rod engaging both flotation modules for forcingsaid annular sealing surface and said spherical surface together in asealing relationship;

a resilient ring carried on said annular sealing surface for ensuringsaid sealing relationship;

a grease coating said resilient sealing ring and said spherical surfacefurther ensuring said sealing relationship;

ing chamber and for maintaining said passageway.

1. An apparatus for coupling the submerged portions of flotation modulescomprising: means providing a spherical surface disposed on thesubmerged portion of one flotation module; means carried on thesubmerged portion of an adjacent flotation module for defining awater-filled cylindrically-shaped cavity integrally extending from saidadjacent flotation module, both flotation modules are provided withopenings in communication with said cavity and after the water has beenevacuated, create a passageway between the flotation modules; meansmounted on the outwardmost extreme of the means defining a cavityforming an annular sealing surface having a crosssectional radiuscorresponding to said spherical surface; at least one tensioning rodengaging both flotation modules for forcing said annular sealing surfaceand said spherical surface together in a sealing relationship; aresilient ring carried on said annular sealing surface for ensuring saidsealing relationship; a grease coating said resilient sealing ring andsaid spherical surface further ensuring said sealing relationship; meansfor evacuating the water from the cavity creating an area of lowerpressure and thereby affecting said coupling; and a plurality ofreinforcing bars extending from each flotation module within acylindrical casting chamber coaxially insiDe of a cylindrically-shapedmember enclosing said cavity and a casting material fills said castingchamber for further ensuring the coupling of flotation modules.
 2. Anapparatus according to claim 1 in which there is provided a cofferdamwall coaxially inwardly disposed with respect to saidcylindrically-shaped member for defining the inner diameter of saidcylindrical casting chamber and for maintaining said passageway.